You wouldn’t be blamed for overlooking it in favor of the bigger cards. Ahead of the major shows scheduled for July 19, on July 16, at Sydney’s Qudos Bank Arena, one fight card featured the return of rugby legend Sonny Bill Williams. The 40-year-old was part of the team that won the Rugby World Cup twice. But he’s also an avid boxer, holding a 9-2 professional record. Williams returned to the ring nearly three years after his loss to kickboxing legend Mark Hunt. Stories like these are rare. Athletes from other disciplines are choosing the rigor and discipline of boxing. Still, there are a few other shining examples.

Back in the United States, several NBA and NFL legends developed a strong interest in the sweet science. They may not have reached the highest levels in boxing. Still, their stories prove that interdisciplinary crossover need not be dismissed. In fact, if Mike Tyson‘s son is to be believed, a few of them might have reached, or even won, a championship had they chosen boxing as their primary path.

Amir Tyson‘s remarks came in response to a post featuring a short clip of basketball icon Shaquille O’Neal sparring with former heavyweight champion Oliver McCall. “There are so many NFL and NBA players who could have been championship material if they did that profession and not what they actually did,” his Instagram Story read.

Under the supervision of Freddie Roach, O’Neal and McCall engaged in a surprisingly fierce sparring session. Of course, the NBA legend had a clear height and reach advantage, even managing to push the heavyweight fighter to the ropes. Still, McCall’s experience likely helped him escape unscathed. He noted, however, that O’Neal was highly competitive in the ring. Just as he was on the court.

Alongside Hasim Rahman, McCall remains one of the only heavyweights to have defeated the legendary Lennox Lewis. Remarkably, he returned to the ring last year at the age of 59. Just three months later, he faced his 77th opponent, less than two months before his 60th birthday.

The level of athleticism required in sports like the NFL and NBA perhaps prepares athletes to withstand the brutal demands of the boxing ring.

Pushing beyond the limits

For the record, Shaquille O’Neal has trained in multiple combat sports disciplines, including boxing. On a previous occasion, he laced up the gloves to face none other than Oscar De La Hoya. Part of a 2009 TV series called ‘Shaq vs.,’ the two squared off in an exhibition match. Although he lost, reports suggest O’Neal might have gone easy on the former world champion-turned-promoter. The following year, the NBA legend faced ‘Sugar’ Shane Mosley and again lost by unanimous decision.

A closer look reveals that quite a few NFL players have laced up the gloves to pursue their boxing dreams. One of the most notable names to make the switch from the gridiron is former New York Jets star Mark Gastineau, who compiled a 15-2 record. Interestingly, one of his two losses came at the hands of another footballer-turned-boxer, Alonzo Highsmith.

Admittedly, for some, it may have been the payday and glory that lured them into considering a switch to boxing. But for others, like Shaquille O’Neal, it might be about something deeper. “In order to be the best, you have to learn from the best,” he said.

Do you think the physicality and intensity of the NFL and NBA could help prepare athletes for a career in boxing?